Last update : 12/1/2004

center - center

### Calling Sequence

  `s=center(x)`
  `s=center(x,'r') or s=center(x,1)`
  `s=center(x,'c') or s=center(x,2)`

### Parameters

- ``x: real or complex vector or matrix

### Description

This function computes `s`, the centred version of the numerical matrix `x`. For a vector or a matrix `x`, `s=center(x)` returns in the `(i,j)` coefficient of the matrix `s` the value `(x(i,j)-xbar)`, where `xbar` is the mean of the values of the coefficients of `x`. `s=center(x,'r')` (or, equivalently, `s=center(x,1)`) is the rowwise center reduction of the values of `x`. It returns in the entry `s(i,j)` the value `(x(i,j)-xbarv(j))(j)` with `xbarv(j)` the mean of the values of the `j` column. `s=center(x,'c')` (or, equivalently, `s=center(x,2)`) is the columnwise center reduction of the values of `x`. It returns in the entry `s(i,j)` the value `(x(i,j)-xbarh(i)))` with `xbarh(i)` the mean of the values of the `i` row.

### Examples

    x=[0.2113249  0.0002211 0.6653811;
       0.7560439  0.3303271 0.6283918]
    s=center(x)
    s=center(x,'r')
    s=center(x,'c')

### See Also

`wcenter`,

### Author

Carlos Klimann